"All those insults and changes from climate disruption add up quickly:

$15 billion for Midwest farmers staring at a year of crop loss and rebuilding as the Mississippi River floods.
The lower the estimated cost of disruption, the less action the Obama Administration can justify.

600 deaths and 1,000 hospitalizations as a heat wave bakes Chicago.

$147 million gone as Alaska's king crab fishery succumbs to acidification and changing prey/predator structures.

The total cost of climate change seems impossible to pin down, given the uncertainties. But an assortment of climate researchers and economists are now chasing after that sum, attempting to arrive at a bottom line.

In February an inter-agency workgroup released the administration's best guess of what each ton of carbon dioxide dumped in the atmosphere costs society: $21, plus or minus, or roughly $121 billion worth of damages annually as a result of U.S. carbon dioxide emissions [pdf].

Until this summer, the exercise was mostly academic. No more. The death of cap-and-trade and the shift in Congress following the mid-term elections means that bottom line has the potential to shape U.S. climate policy for the foreseeable future."